Update dependencies

Update to `node16`.

Context: https://github.blog/changelog/2022-09-22-github-actions-all-actions-will-begin-running-on-node16-instead-of-node12/

Update dependencies

Await install64bitDependencies

Otherwise, builds do not fail if apt-get fails for example (see actions/toolkit#737).

Various improvements and bug fixes

- Rename smalltalk-version to smalltalk-image
- Validate Smalltalk image selection (fixes #10)
- Refactor code

Disable env var support on Windows

- Use child_process again
- Refactor code

Find and export smalltalkCI’s env vars